Abstract: A semiconductor device includes as part of the integrated circuit thereof a test structure which allows testing of the semiconductor device through the device pins, to allow adjustment of various parameters of the circuit if desired for obtainment of optimum performance, and with the circuit being operable under normal conditions without degradation in relation to its optimum design situation.

Abstract: This invention discloses an oscillator circuit wholly contained in a single integrated circuit and implemented in compound semiconductor technology, wherein the oscillation frequency thereof is substantially stable over variations in supply voltage, process variations in fabrication, and temperature.

Abstract: This invention discloses a logic circuit including first, second and third transistors with the control terminals of two of those transistors being connected to the input signal lead, with the output signal lead being connected to one of the current handling terminals of one of those transistors, and with a load device connected to the respective current handling terminals of those two transistors and one of the voltage supply terminals.

Abstract: This invention discloses a push pull logic circuit which includes a capacitor connected to the output signal lead of the circuit, and also a plurality of diodes, in parallel with the capacitor and connected to the output signal lead.

Abstract: This invention discloses a TTL compatible output buffer circuit which provides that in the state where the output signal thereof is high, no substantial current is provided inward of the buffer circuit from the output signal lead over a wide range of voltages applied to the output signal lead, including applied voltages substantially greater than that supplied by the voltage supply terminals of the circuit, with the circuit being further implemented in compound semiconductor technology.

Abstract: This invention discloses a TTL compatible input buffer which includes means for preventing appreciable current flow into the buffer circuit upon input voltage being supplied to the input signal lead which is substantially above the voltages supplied to the voltage supply terminals of the circuit.

Abstract: A programmable sequencer 10 uses an input mapping circuit 20 including a programmable logic array 30 to map decision variable input conditions onto branch address signals, which are used with primary address signals to form a next state address for state word memory 50. Input mapping circuit 20 preferably includes a branch control circuit 40, controlled by feedback signals from the output of state word memory 50, to selectively transform branch address signals to allow different states to use state word locations sharing the same primary address in state word memory 50. The preferred embodiment also includes a diagnostic circuit 80 useful for programming, and/or diagnosing operation of, sequencer 10.

Abstract: An output circuit (50) is provided for a programmable logic array (PLA) integrated circuit. The output circuit (50) includes a flip flop (52) which stores a given output term from the array. The flip flop (52) contains a set input lead (S) and a reset input lead (R). The signals present at the set input, reset input, the clock leads are generated by programmable logic within the PLA. A multiplexer (54) is provided which receives the output data of the flip flop (52) and the signal constituting the input data for the flip flop. The multiplexer provides the data input signal on the multiplexer output lead (60) when both the set and reset input signals are true. However, if either or both the set and reset input signals are false, then the multiplexer (54) provides the Q output signal from the flip flop (52) on the multiplexer output lead (60). The multiplexer output signal is presented to a three-state buffer (62) which in turn drives an output pin.

Abstract: A field programmable array logic circuit is described wherein existing sensing circuitry is employed along with circuitry to enable every fuse location to be isolated, so that both a.c. and verification testing takes place under the same conditions, i.e. voltage levels and frequency, which occurs during normal operation of the programmed circuit.